NEW HAVEN -- A 21-year-old woman is in stable condition following what authorities described as a "vicious domestic assault" Thursday that allegedly went unreported by others in the victim's home, police said.

The victim, who was severely beaten and stabbed, was taken to Yale-New Haven Hospital by ambulance, where staff reported the assault to police around 3:30 p.m., according to Officer David Hartman, police spokesman.

Josue Martinez, 23, also of New Haven, was charged with first-degree domestic assault, Hartman said.

At Martinez's home on Norwood Drive, investigators searched Martinez's basement bedroom and "found blood spattered walls and other evidence of a vicious attack," Hartman said in a statement. Detectives Daniel Sacco and Michael Torre also are on the case, as Officer John Kaczor, the initial officer to speak to Martinez, requested the involvement of the Investigative Services Division, Hartman said.

"Interviews with (the victim's) family members painted a story of chronic domestic assaults and disputes," and investigators "learned that the couple often slept in a car in the driveway rather than inside. Martinez admitted this to Officer Kaczor -- adding it was due to his heroin addiction. His mother, whose house it is, doesn't want them there," police said in the statement.

"As other interviews concluded, it was learned several others had been home at the time. One said she'd heard moaning. Others said they'd heard the fighting, but then the noise stopped, and they didn't check up on what they'd heard or phone police," Hartman said in the statement.

The victim's injuries are not believed to be life-threatening, police said.

While police said they have evidence of an attack, Martinez told a different story.

As police had begun to investigate, Martinez arrived at the hospital and told Kaczor he had awakened alone at about 2 p.m. at his mother's house in the city, Hartman said.

Martinez told Kaczor that his girlfriend arrived at the house "barely conscious, and badly beaten," and told him she had been jumped, police said. Martinez claimed that while he tried to call 911, the girlfriend had "tumbled down the staircase to the basement floor. [Martinez] said she was unconscious and he tried reviving her by slapping her face," Hartman said in the statement.

Martinez told police that EMTs arrived and attended to his girlfriend, but he did not go with her to the hospital, and drove himself there, Hartman said.

Police said that as the victim was not able to speak, Martinez was asked to accompany investigators to police headquarters for an interview. "When they questioned the truthfulness of the story, Martinez stopped talking. His bloodied cloths were taken as evidence, and he was provided a Tyvek suit to wear," police said.

The investigation is ongoing and additional charges could be filed, police said.

Martinez's car also was impounded as potential evidence and was towed from the hospital parking lot, police said.

During his detention, Martinez "attempted to harm himself in his cell" and was taken to an area hospital for psychiatric evaluation, police said. He remains under police guard.